With the growth of technology and internet use, consumers are increasingly shifting toward online shopping. E-commerce platforms have created useful and practical online transactions for products across borders. The number of sellers on e-commerce platforms has also increased significantly in recent years. Naturally, the larger the supply of online products, the greater the risk of possible IP infringement online. While this has made shopping more accessible and convenient for many, it has also created significant opportunities for fraudulent sellers. These fraudulent sellers are often anonymous, and it can be hard to identify them or hold them to account. As a result, some intellectual property (IP) owners have tried to hold e-commerce platforms responsible, raising questions as to what legal liability e-commerce platforms have for content posted by users. In March 2022, the Central Intellectual Property and International Trade Court (IP&IT Court) issued a landmark judgment finding a world-leading e-commerce platform not liable for a third party’s alleged IP infringement on its platforms. Contributory infringement IP can be infringed directly by the person who sells or manufactures the infringing product, or indirectly by a party that encourages or contributes to the infringing act. At present, Thai IP law does not contain any clear provisions on contributory infringement by e-commerce platforms and, until recently, there were no clear court judgments on this issue. One recent development in this area in Thailand has been the adoption of the Copyright Act (No. 5) B.E. 2565 (2022), which will come into effect on August 23, 2022. This act provides that internet service providers will not be liable for copyright-infringing materials posted by users, provided they comply with certain legal requirements. However, there are currently no equivalent provisions relating to patents, trademarks, or other types of IP rights. The closest applicable legislation is Section 432